U.S. patent application number 17/056790 was filed with the patent office on 2021-07-08 for peroxide crosslinkable fluororubber composition.
This patent application is currently assigned to NOK CORPORATION. The applicant listed for this patent is NOK CORPORATION. Invention is credited to Shingo KAWANO, Hideto KOMURASAKI.
Application Number | 20210206955 17/056790 |
Document ID | / |
Family ID | 1000005481680 |
Filed Date | 2021-07-08 |
United States Patent
Application |
20210206955 |
Kind Code |
A1 |
KOMURASAKI; Hideto ; et
al. |
July 8, 2021 |
PEROXIDE CROSSLINKABLE FLUORORUBBER COMPOSITION
Abstract
A peroxide crosslinkable fluororubber composition comprising:
(A) 0.1 to 2.5 parts by weight of a sodium salt or potassium salt
of a saturated or unsaturated higher fatty acid; (B) (a) 0.1 to 3.5
parts by weight of a fluoropolyether derivative having a melting
point of 70.degree. C. or less, (b) 0.1 to 3.0 parts by weight of a
poly-.alpha.-olefin oligomer, or (c) 0.1 to 2.0 parts by weight of
an alkylamine compound having 4 to 30 carbon atoms; and (C) 0.1 to
5 parts by weight of an organic peroxide, based on 100 parts by
weight of peroxide crosslinkable fluororubber. This fluororubber
composition has excellent crosslinking rate, mold release
properties, hardness, compression set characteristics, and the like
that are required for molding processability.
Inventors: |
KOMURASAKI; Hideto;
(Kumamoto, JP) ; KAWANO; Shingo; (Kumamoto,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NOK CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
NOK CORPORATION
Tokyo
JP
|
Family ID: |
1000005481680 |
Appl. No.: |
17/056790 |
Filed: |
May 29, 2019 |
PCT Filed: |
May 29, 2019 |
PCT NO: |
PCT/JP2019/021362 |
371 Date: |
November 19, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08L 27/18 20130101;
C08L 2312/00 20130101; C09K 2200/0642 20130101; C08L 27/20
20130101; C08L 2205/03 20130101; C08L 27/16 20130101; C09K
2200/0657 20130101; C09K 3/1009 20130101 |
International
Class: |
C08L 27/16 20060101
C08L027/16; C08L 27/18 20060101 C08L027/18; C08L 27/20 20060101
C08L027/20; C09K 3/10 20060101 C09K003/10 |
Foreign Application Data
Date |
Code |
Application Number |
May 30, 2018 |
JP |
2018-103594 |
Claims
1. A peroxide crosslinkable fluororubber composition comprising:
(A) 0.1 to 2.0 parts by weight of a sodium salt or potassium salt
of a saturated or unsaturated higher fatty acid; (B) (a) 0.1 to 2.5
parts by weight of a fluoropolyether derivative having a melting
point of 70.degree. C. or less, (b) 0.1 to 2.0 parts by weight of a
poly-.alpha.-olefin oligomer, or (c) 0.1 to 1.0 parts by weight of
an alkylamine compound having 4 to 30 carbon atoms; and (C) 0.1 to
5 parts by weight of an organic peroxide, based on 100 parts by
weight of peroxide crosslinkable fluororubber having an iodine atom
and/or a bromine atom in a polymer main chain and/or side
chain.
2. The peroxide crosslinkable fluororubber composition according to
claim 1, wherein the peroxide crosslinkable fluororubber is a
copolymer elastomer in which an iodine group and/or a bromine group
is introduced into a copolymer elastomer having a ternary or binary
copolymer composition of 50 to 80 mol % of vinylidene fluoride, 15
to 50 mol % of hexafluoropropylene, and 30 to 0 mol % of
tetrafluoroethylene.
3. The peroxide crosslinkable fluororubber composition according to
claim 1, wherein the processing aids (A) and (B) are used with
their total amount being at a ratio of 0.5 to 3.0 parts by weight,
based on 100 parts by weight of the peroxide crosslinkable
fluororubber.
4. The peroxide crosslinkable fluororubber composition according to
claim 1, wherein the sodium salt or potassium salt of a saturated
or unsaturated higher fatty acid is a sodium salt or potassium salt
of a saturated or unsaturated higher fatty acid, having 8 to 18
carbon atoms.
5. The peroxide crosslinkable fluororubber composition according to
claim 4, wherein the higher fatty acid is a higher fatty acid
derived from oils and fats.
6. The peroxide crosslinkable fluororubber composition according to
claim 1, wherein the poly-.alpha.-olefin oligomer is an oligomer of
.alpha.-olefin having 3 or more carbon atoms.
7. The peroxide crosslinkable fluororubber composition according to
claim 1, which is used as a molding material for sealing
material.
8. A sealing material obtained by crosslinking and molding the
peroxide crosslinkable fluororubber composition according to claim
7.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a peroxide crosslinkable
fluororubber composition. More particularly, the present disclosure
relates to a peroxide crosslinkable fluororubber composition having
excellent crosslinking rate, mold release properties, hardness,
compression set characteristics, and the like that are required for
molding processability.
BACKGROUND ART
[0002] Fluororubber is relatively expensive and has poor
processability up to the molding process; thus, high processing
cost is required. Various improvement efforts have been made to
reduce the product cost.
[0003] As such an improvement method, selection to reduce the raw
material cost so as to obtain effects directly is considered;
however, it is difficult to reduce the cost with a satisfactory raw
material quality. This method is not suitable for ensuring the
quality of functional rubber parts.
[0004] On the other hand, there is a method of improving
processability in order to reduce the cost in the production
process. In particular, shortening the vulcanization time in the
molding process, high mold release properties, and a reduction of
burr formation, directly affect the productivity of products, and
thus are expected to be effective in facilitating the cost
reduction. Although such an improvement can be achieved by
installing equipment, it is not easy because the equipment cost
greatly affects the production cost. In many cases, an improvement
is achieved by the compounding composition of rubber compounds.
[0005] As an improvement method with the compounding composition,
there is a method of selecting a fluororubber polymer that is said
to have good processability; however, it is difficult to
sufficiently exhibit processability for unique production processes
of rubber part manufacturers. An improvement method by adding a
processing aid is required. There are various processing aids used
in such a method; however, they each had different improvement
effects, and it was thus difficult to sufficiently satisfy some
types of required processability by adding them alone.
[0006] Further, silicone-based processing aids have a great effect
of improving processability and are preferably used. However, they
may be used in or near electronic parts depending on the use
environment of products, and problematically cause contamination.
For this reason, non-silicone-based processing aids have been
increasingly demanded recently. Thus, in the actual circumstances,
it is difficult to use silicone-based processing aids without
careful consideration.
[0007] Patent Document 1 proposes a fluororubber composition
comprising 0.8 to 4.0 parts by weight of a glycerol ester of an
unsaturated fatty acid having 14 to 20 carbon atoms based on 100
parts by weight of fluororubber. Patent Document 1 indicate that
this fluororubber composition can provide a crosslinked
fluororubber article having exceptional surface smoothness while
maintaining rubber properties such as strength.
[0008] However, as shown in the results of Comparative Example 12
provided later, when glycerol monooleate ester is compounded, the
vulcanization rate, mold release properties, hardness difference,
and compression set do not show desired results. Moreover, even
when glycerol monooleate ester is used in combination with calcium
stearate or beef tallow hardened fatty acid potassium (Comparative
Examples 17 and 18), the vulcanization rate and hardness difference
(and compression set) are not satisfied.
[0009] Patent Document 1 indicates that as processing aids other
than glycerol esters, alkali metal salts and the like of higher
fatty acids can be used as mold release property improving agent.
In all of the Examples and Comparative Examples, a
tetrafluoroethylene-propylene copolymer is used as fluororubber,
and sodium stearate is also used as a processing aid for normal
state physical properties and surface smoothness; however, calcium
stearate is used in many examples.
[0010] In Comparative Example 5 provided later, in which calcium
stearate is used alone, the vulcanization rate, O ring thickness,
and hardness difference are not satisfied. In Comparative Example
17, in which calcium stearate is used in combination with glycerol
monooleate ester, the vulcanization rate, hardness difference, and
compression set are not satisfied, as described above.
PRIOR ART DOCUMENT
Patent Document
[0011] Patent Document 1: WO 2016/084862 A1
[0012] Patent Document 2: JP-A-2001-354986
OUTLINE OF THE INVENTION
Problem to be Solved by the Invention
[0013] An object of the present disclosure is to provide a peroxide
crosslinkable fluororubber composition having excellent
crosslinking rate, mold release properties, hardness, compression
set characteristics, and the like that are required for molding
processability.
Means for Solving the Problem
[0014] The above object of the present disclosure can be achieved
by a peroxide crosslinkable fluororubber composition
comprising:
[0015] (A) 0.1 to 2.5 parts by weight of a sodium salt or potassium
salt of a saturated or unsaturated higher fatty acid;
[0016] (B) (a) 0.1 to 3.5 parts by weight of a fluoropolyether
derivative having a melting point of 70.degree. C. or less, [0017]
(b) 0.1 to 3.0 parts by weight of a poly-.alpha.-olefin oligomer,
or [0018] (c) 0.1 to 2.0 parts by weight of an alkylamine compound
having 4 to 30 carbon atoms; and
[0019] (C) 0.1 to 5 parts by weight of an organic peroxide, based
on 100 parts by weight of peroxide crosslinkable fluororubber.
Effect of the Invention
[0020] Due to the combined use of two types of processing aids (A)
and (B), the peroxide crosslinkable fluororubber composition
according to the present disclosure has excellent crosslinking
rate, mold release properties, hardness, compression set
characteristics, and the like that are required for molding
processability, and can be thus effectively used as molding
materials for various crosslinked and molded articles, particularly
sealing materials.
EMBODIMENTS FOR CARRYING OUT THE INVENTION
[0021] The peroxide crosslinkable fluororubber used is a copolymer
of a fluorine-containing unsaturated monomer having an iodine atom
and/or a bromine atom in a polymer main chain and/or side
chain.
[0022] Examples of the fluorine-containing unsaturated monomer
include tetrafluoroethylene, vinylidene fluoride,
hexafluoropropylene, trifluoroethylene, chlorotrifluoroethylene,
1,1,3,3,3-pentafluoropropylene, perfluoro(methylvinyl ether),
perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), and
the like.
[0023] Examples of the peroxide crosslinkable fluororubber include
a vinylidene fluoride-hexafluoropropylene copolymer, a vinylidene
fluoride-tetrafluoroethylene-hexafluoropropylene terpolymer, a
vinylidene fluoride-tetrafluoroethylene-perfluoro(methyl vinyl
ether) terpolymer, a tetrafluoroethylene-ethylene-perfluoro(methyl
vinyl ether) terpolymer, a tetrafluoroethylene-propylene copolymer,
a vinylidene fluoride-propylene copolymer, a
tetrafluoroethylene-vinylidene fluoride-propylene terpolymer, and
the like.
[0024] In addition to the above fluorine-containing unsaturated
monomers, a fluorine-containing unsaturated monomer for modifying
the characteristics of fluororubber may be copolymerized at a ratio
of 3 wt. % or less. Examples of the fluorine-containing unsaturated
monomer for modifying the characteristics of fluororubber include
fluorine-containing diene compounds, such as
perfluoro(3,6-dioxa-1,7-octadiene),
3,3,4,4,5,5,6,6-octafluoro-1,7-octadiene, and
3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-hexadecafluoro-1,9-decadiene.
[0025] Further, a non-fluorine unsaturated monomer, such as
propylene or ethylene, may be copolymerized at a ratio of 30 wt. %
or less.
[0026] It is preferable to use a copolymer elastomer in which an
iodine group and/or a bromine group is introduced into a copolymer
elastomer having a ternary or binary copolymer composition of about
50 to 80 mol % of vinylidene fluoride [VdF], about 15 to 50 mol %
of hexafluoropropylene [HFP], and about 30 to 0 mol % of
tetrafluoroethylene [TFE]. Moreover, cold resistant fluororubber,
which is a perfluoroalkyl group-containing copolymer elastomer,
super cold resistant fluororubber, which is a perfluoromethoxy
vinyl ether-containing copolymer elastomer, and the like can also
be used.
[0027] In practice, commercial products, such as Viton GAL200S,
GBL200S, GBL600S, GF200S, and GF600S, produced by Du Pont;
Tecnoflon P454, P757, P459, and P952, produced by Solvay Specialty
Polymers; and DAI-EL G952, G901, G902, G912, and G801, produced by
Daikin Industries, Ltd.; are used as they are.
[0028] An iodine atom and/or a bromine atom, which are crosslinking
sites of the peroxide crosslinkable fluororubber, can be introduced
into the polymer main chain terminal by carrying out the
polymerization reaction in the presence of a fluorine-containing
dihalogen compound, such as 1,4-diiodooctafluorobutane or
1-bromo-2-iodotetrafluoroethane. When monohalogeno
fluorine-containing ethylene, such as 1-iodotrifluoroethylene,
1,1-difluoro-2-iodoethylene, or 1,1-difluoro-2-bromoethylene, is
copolymerized, an iodine atom or a bromine atom can be introduced
into the inside of the polymer main chain. When
perfluoro(2-bromoethyl vinyl ether),
4-iodo-3,3,4,4-tetrafluoro-1-butene, or the like is copolymerized,
an iodine atom or a bromine atom can be introduced into the polymer
side chain.
[0029] Examples of the organic peroxide crosslinking agent, which
is used to crosslink the peroxide crosslinkable fluororubber,
include dialkyl peroxides, such as dicumyl peroxide,
di-tert-butylperoxide,
2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,
2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and
1,3-bis(tert-butylperoxy isopropyl)benzene; diacyl peroxides, such
as benzoyl peroxide and isobutyryl peroxide; peroxyesters, such as
2,5-dimethyl-2,5-bis(benzoylperoxy)hexane and tert-butylperoxy
isopropyl carbonate; and the like. Among these,
2,5-dimethyl-2,5-di(tert-butylperoxy)hexane is preferable. These
can be used singly or in combination of two or more.
[0030] The organic peroxide crosslinking agent is used at a ratio
of about 0.1 to 5 parts by weight, preferably about 0.3 to 3 parts
by weight, based on 100 parts by weight of the peroxide
crosslinkable fluororubber. If the use ratio is less than this
range, the crosslinking of the fluororubber is insufficient, which
may lead to a reduction in the mechanical properties of the
crosslinked product. In contrast, if the organic peroxide
crosslinking agent is used at a ratio larger than this range,
excessive crosslinking progresses, which may lead to a reduction in
the physical properties, such as elongation of the crosslinked
product.
[0031] A polyfunctional unsaturated compound, such as triallyl
isocyanurate, is used as a crosslinking aid for the peroxide
crosslinkable fluororubber. The compounding amount thereof is about
0.1 to 10 parts by weight, preferably about 1 to 5 parts by weight,
based on 100 parts by weight of the peroxide crosslinkable
fluororubber. If the use ratio is less than this range,
crosslinking is insufficient, which may make the shape retention of
the crosslinked product difficult, or may lead to a reduction in
the mechanical properties of the crosslinked product. In contrast,
if the polyfunctional unsaturated compound is used at a ratio
larger than this range, improvement of various characteristics,
such as mechanical properties and heat resistance, cannot be
expected, which is uneconomical.
[0032] As the sodium salt or potassium salt of a saturated or
unsaturated higher fatty acid of the processing aid (A), Na salts
or K salts of higher fatty acids having 8 to 18 carbon atoms, such
as stearic acid, palmitic acid, oleic acid, linolic acid, and
linolenic acid, are used as they are. The higher fatty acid is
preferably a higher fatty acid derived from oils and fats. The
combined use of the processing aid (A) with a lower aliphatic
monocarboxylic acid metal salt is also effective.
[0033] In practice, commercial products, such as NS-Soap produced
by Kao Corporation, which is a beef tallow hardened fatty acid
sodium salt, Nonsoul SK-1 produced by NOF Corporation, which is
beef tallow hardened fatty acid potassium, and SS-40N produced by
Kao Corporation, which is a higher fatty acid sodium salt, are used
as they are.
[0034] The processing aid (A) is used at a ratio of about 0.1 to
2.5 parts by weight, preferably about 0.2 to 2.0 parts by weight,
more preferably about 0.2 to 1.0 part by weight, based on 100 parts
by weight of the peroxide crosslinkable fluororubber. If the
compounding ratio is less than this range, the object of the
present disclosure cannot be achieved. In contrast, if the
processing aid (A) is compounded at a ratio larger than this range,
the compression set characteristics is deteriorated.
[0035] When a mixture mainly comprising a lower aliphatic
monocarboxylic acid metal salt having 1 to 5 carbon atoms, such as
TE58A produced by Technical Processing, is used in combination, it
is used at a ratio of about 0.1 to 2.0 parts by weight, preferably
about 0.1 to 1.5 parts by weight, more preferably about 0.1 to 1.0
part by weight, based on 100 parts by weight of the peroxide
crosslinkable fluororubber.
[0036] These higher fatty acid metal salt-based compounds increased
the crosslinking rate and improved the mold release properties;
however, the effect for flowability was low, and molded articles
tended to have a large size. Therefore, it was still insufficient
to easily adjust the balance among the crosslinking rate,
flowability, and mold release properties.
[0037] In order to improve such a point, at least one of the
following compounds (a), (b), and (c) is used as a processing aid
(B) in combination with the processing aid (A).
[0038] As the fluoropolyether derivative of the processing aid (a),
for example, one represented by the general formula:
RfO(CF.sub.2O).sub.p(C.sub.2F.sub.4O).sub.q(C.sub.3F.sub.6O).sub.rRf
[0039] Rf: a lower perfluoroalkyl group having 1 to 5 carbon atoms
(Patent Document 2) is used. In practice, commercial products, such
as FPA1 produced by Solvay Specialty Polymers, are used as they
are. As the processing aid (a), one having a melting point of about
70.degree. C. or less is used. If a processing aid having a melting
point higher than this range is used, it cannot be dispersed during
the preparation of the composition, and dispersion may be
insufficient. In particular, in the case of addition using an open
roll, handling is difficult because the temperature is less likely
to increase.
[0040] The processing aid (a) is used at a ratio of about 0.1 to
3.5 parts by weight, preferably about 0.2 to 2.5 parts by weight,
more preferably about 0.2 to 2.0 parts by weight, based on 100
parts by weight of the peroxide crosslinkable fluororubber. If the
compounding ratio is less than this range, the object of the
present disclosure cannot be achieved. In contrast, if the
processing aid (a) is compounded at a ratio larger than this range,
the compression set characteristics is deteriorated.
[0041] As the poly-.alpha.-olefin oligomer of the processing aid
(b), oligomers of .alpha.-olefins having 3 or more carbon atoms,
preferably .alpha.-olefins having 3 to 16 carbon atoms, such as
oligomers of homopolymers or copolymers of polypropylene and
polybutene, are used. In practice, commercial products, such as
Dyurasin 128 produced by INEOS, are used as they are.
[0042] The processing aid (b) is used at a ratio of about 0.1 to
3.0 parts by weight, preferably about 0.2 to 2.0 parts by weight,
more preferably about 0.2 to 1.0 part by weight, based on 100 parts
by weight of the peroxide crosslinkable fluororubber. If the
compounding ratio is less than this range, the object of the
present disclosure cannot be achieved. In contrast, if the
processing aid (b) is compounded at a ratio larger than this range,
the compression set characteristics is deteriorated.
[0043] As the alkylamine having 4 to 30 carbon atoms of the
processing aid (c), for example, stearylamine, octadecylamine, or
the like is used. In practice, commercial products, such as Farmin
80 produced by Kao Corporation and HT290 produced by
ScHill+Seilacher, are used as they are.
[0044] The processing aid (c) is used at a ratio of about 0.1 to
2.0 parts by weight, preferably about 0.2 to 1.0 part by weight,
more preferably about 0.2 to 0.5 parts by weight, based on 100
parts by weight of the peroxide crosslinkable fluororubber. If the
compounding ratio is less than this range, the object of the
present disclosure cannot be achieved. In contrast, if the
processing aid (c) is compounded at a ratio larger than this range,
the compression set characteristics is deteriorated.
[0045] The total amount of the processing aids (A) and (B) must be
about 0.2 to 5.0 parts by weight, preferably about 0.3 to 3.5 parts
by weight, more preferably about 0.5 to 2.0 parts by weight, based
on 100 parts by weight of the peroxide crosslinkable fluororubber.
If the compounding ratio is less than this range, the object of the
present disclosure cannot be achieved. In contrast, if they are
compounded at a ratio larger than this range, the compression set
characteristics is deteriorated.
[0046] In addition to the above essential components, the peroxide
crosslinkable fluororubber composition can be compounded with
compounding agents that are generally used in the field of rubber
processing. Examples of such compounding agents include inorganic
fillers such as carbon black and silica, acid acceptors,
crosslinking accelerators, light stabilizers, plasticizers, other
processing aids, smoothing agents, pressure-sensitive adhesives,
lubricants, flame retardants, antifungal agents, antistatic agents,
coloring agents, silane coupling agents, crosslinking retardants,
and the like. The compounding amounts of these compounding agents
are not particularly limited within a range that does not inhibit
the object and effect of the present disclosure, and they can be
suitably compounded in amounts depending on the compounding
purpose.
[0047] The peroxide crosslinkable fluororubber composition can be
prepared by compounding peroxide crosslinkable fluororubber with
processing aids (A) and (B), an organic peroxide crosslinking agent
(C), a polyfunctional unsaturated compound crosslinking aid, and
optionally compounding agents described above using a Banbury
mixer, a pressurizing kneader, an open roll, or the like.
[0048] The prepared composition is generally crosslinked by press
crosslinking (primary crosslinking). Hot press is generally
performed at a temperature of about 140 to 200.degree. C. at a
pressure of about 0.2 to 15 MPa for about 5 to 60 minutes. When the
primary crosslinking is further carried out by postcure (secondary
crosslinking), the mechanical properties, compression set, etc., of
the crosslinked product can be improved.
EXAMPLES
[0049] The following describes the present disclosure with
reference to Examples.
Example 1
TABLE-US-00001 [0050] Peroxide crosslinkable VdF-TFE-HFP terpolymer
100 parts by weight (Tecnoflon P757, produced by Solvay Specialty
Polymers) Carbon black (N990, produced by Cancarb 25 parts by
weight Limited) Triallyl isocyanurate (TAIC, produced by Nippon 2.5
parts by weight Kasei Chemical Co., Ltd.) Organic peroxide (Perhexa
25B, produced by 0.5 parts by weight NOF Corporation) Beef tallow
hardened fatty acid potassium 0.7 parts by weight (Nonsoul SK-1,
produced by NOF Corporation) Fluoropolyether derivative (FPA1,
produced by 0.7 parts by weight Solvay Specialty Polymers, melting
point: 50 to 60.degree. C.)
The above-mentioned components other than the organic peroxide were
each kneaded using a 1 L kneader or an open roll at 100.degree. C.
or less for 10 to 30 minutes. Then, the organic peroxide was added
and kneaded using a 1 L kneader or an open roll at 100.degree. C.
or less for 5 to 10 minutes, thereby producing an uncrosslinked
rubber sheet through the open roll.
[0051] The uncrosslinked rubber sheet was subjected to press
crosslinking (primary crosslinking) at 180.degree. C. for 6 minutes
and oven crosslinking (secondary crosslinking) at 230.degree. C.
for 24 hours, and measured or evaluated for each of the following
items. An O ring for fixing was crosslinked and molded in the shape
of the bearing number G25 according to JIS B2401-1: 2012
corresponding to ISO 3601-1: 2008.
[0052] Crosslinking time difference: a value obtained by
subtracting the t90 value of the processing aid-free compounding
(Comparative Example 1) from the t90 value of each Example or each
Comparative Example was calculated as the crosslinking time
difference.
[0053] When the value was less than -10 seconds, it was effective
to increase the crosslinking rate, which was evaluated as
.largecircle..
[0054] When the value was -10 seconds or more, it delayed or was
less effective to increase the crosslinking rate, which was
evaluated as X.
[0055] G25 O ring outer diameter thickness: the average value of
N=3 was calculated.
[0056] An O ring outer diameter thickness of 3.1.+-.0.03 mm was
evaluated as .largecircle..
[0057] An O ring outer diameter thickness outside the above range
was evaluated as X.
[0058] G25 O ring mold release properties: The mold release
properties of the O ring during compression press molding in a mold
with 2.times.5 cavities mold in the G25 shape were evaluated.
[0059] When the O ring was integrally released with less
resistance, and no cut lines occurred between the product and
burrs, this case was evaluated as .largecircle..
[0060] When burrs were cut during mold release, or residues were
formed in the mold, this case was evaluated as X.
[0061] Hardness difference (Shore A instantaneous value): According
to JIS K6253: 2012 corresponding to ISO 7619-1: 2010
[0062] The difference from the value of the processing aid-free
compounding (Comparative Example 1) was calculated.
[0063] A difference of less than +3 points was evaluated as
.largecircle..
[0064] A difference of +3 points or more was evaluated as X.
[0065] Compression set: The O ring in the G25 shape after primary
crosslinking (before secondary crosslinking) (according to JIS
K2401-1: 2012 corresponding to ISO 3601-1: 2008) was cut at two
points to prepare a semi-circular sample having a thickness of
about 3.1 mm. The sample was sandwiched between SUS plates and put
into an oven at 175.degree. C. in a 25% compressed state.
Immediately after heating for 70 hours, the sample was released
from the SUS plates and allowed to stand under room temperature
conditions for 30 minutes. Then, from the changes in the outer
diameter thickness before and after the test, the compression set
value was calculated as the difference from the processing aid-free
compounding (Comparative Example 1) (according to JIS K6262: 2013
corresponding to ISO 815-1: 2008 and ISO 815-2: 2008).
[0066] A numerical value of +3 or less was evaluated as
.largecircle..
[0067] A numerical value of more than +3 was evaluated as X.
Example 2
[0068] In Example 1, of the compounded processing aids (fatty acid
potassium-fluoropolyether derivative), the fluoropolyether
derivative was changed to the same amount (0.7 parts by weight) of
poly-.alpha.-olefin oligomer (Dyurasin 128, produced by INEOS).
Example 3
[0069] In Example 1, of the compounded processing aids (fatty acid
potassium-fluoropolyether derivative), the amount of the
fluoropolyether derivative was changed to 0.5 parts by weight, and
0.2 parts by weight of aliphatic monocarboxylic acid metal salt
mixture (TE58A, produced by Technical Processing), 0.5 parts by
weight of beef tallow hardened fatty acid sodium salt (NS-Soap,
produced by Kao Corporation), and 0.2 parts by weight of fatty acid
sodium salt (SS-40N, produced by Kao Corporation) were used as
fatty acid metal salt-based compounds.
Example 4
[0070] In Example 1, of the compounded processing aids (fatty acid
potassium-fluoropolyether derivative), 0.5 parts by weight of fatty
acid sodium salt (SS-40N) was used in place of the beef tallow
hardened fatty acid potassium, and 0.5 parts by weight of
octadecylamine-containing mixture (HT290, produced by
ScHill+Seilacher) was used in place of the fluoropolyether
derivative.
Example 5
[0071] In Example 1, the compounded processing aids (fatty acid
potassium-fluoropolyether derivative) were changed to 0.7 parts by
weight of fatty acid sodium salt (SS-40N) and 0.3 parts by weight
of stearylamine (Farmin 80, produced by Kao Corporation).
Comparative Example 1
[0072] In Example 1, the processing aid was not used.
Comparative Examples 2 to 16
[0073] In Example 1, only following one kind was used in an amount
of 1.4 parts by weight as the processing aid.
[0074] Comparative Example 2: Aliphatic Monocarboxylic Acid Metal
Salt Mixture (TE58A)
[0075] Comparative Example 3: Beef tallow hardened fatty acid
sodium salt (NS-Soap)
[0076] Comparative Example 4: Beef tallow hardened fatty acid
potassium (Nonsoul SK-1)
[0077] Comparative Example 5: Fatty acid calcium salt (St-Ca,
produced by Showa Chemical Industry Co., Ltd.)
[0078] Comparative Example 6: Alkylbenzenesulfonic acid sodium salt
(DBS-NA, produced by Takemoto Oil & Fat Co., Ltd.)
[0079] Comparative Example 7: Fatty acid sodium salt (SS-40N)
[0080] Comparative Example 8: Stearic acid (produced by Miyoshi Oil
& Fat Co., Ltd.)
[0081] Comparative Example 9: Fatty acid amide (Diamid 0-200,
produced by Nippon Kasei Co., Ltd.)
[0082] Comparative Example 10: Fatty acid ester (VPA #2, produced
by Chemours)
[0083] Comparative Example 11: Pentaerythritol tetrastearate
(Deoflow 821, produced by DOG Chemie)
[0084] Comparative Example 12: Glycerol monooleate ester (a mixture
of Emaster 510P, produced by Riken Vitamin Co., Ltd. and
silica)
[0085] Comparative Example 13: Fluoropolyether derivative
(FPA1)
[0086] Comparative Example 14: Poly-.alpha.-olefin oligomer
(Dyurasin 128)
[0087] Comparative Example 15: Octadecylamine-containing mixture
(HT290)
[0088] Comparative Example 16: Stearylamine (Farmin 80)
Comparative Example 17
[0089] In Example 1, the compounded processing aids (fatty acid
potassium-fluoropolyether derivative) were changed to 1.0 part by
weight of fatty acid calcium salt (St-Ca) and 1.5 parts by weight
of glycerol monooleate ester (Emaster 510P), respectively.
Comparative Example 18
[0090] In Example 1, the compounded processing aids (fatty acid
potassium-fluoropolyether derivative) were changed to 1.0 part by
weight of beef tallow hardened fatty acid potassium (Nonsoul SK-1)
and 1.5 parts by weight of glycerol monooleate ester (Emaster
510P), respectively.
Comparative Example 19
[0091] In Example 1, the compounded processing aids (fatty acid
potassium-fluoropolyether derivative) were changed to 0.7 parts by
weight of fatty acid calcium salt (St-Ca) and 0.7 parts by weight
of fluoropolyether derivative (FPA1), respectively.
Comparative Example 20
[0092] In Example 1, the compounded processing aids (fatty acid
potassium-fluoropolyether derivative) were changed to 0.7 parts by
weight of beef tallow hardened fatty acid sodium salt (NS-Soap) and
0.7 parts by weight of fatty acid ester (VPA #2), respectively.
Comparative Example 21
[0093] In Example 1, the compounded processing aids (fatty acid
potassium-fluoropolyether derivative) were changed to 0.7 parts by
weight of fatty acid sodium salt (SS-40N) and 0.7 parts by weight
of fatty acid ester (VPA #2), respectively.
Comparative Example 22
[0094] In Example 1, the compounded processing aids (fatty acid
potassium-fluoropolyether derivative) were changed to 0.7 parts by
weight of fatty acid sodium salt (SS-40N) and 0.7 parts by weight
of pentaerythritol tetrastearate (Deoflow 821), respectively.
[0095] Following Table shows the results obtained respectively in
the above Examples and Comparative Examples.
TABLE-US-00002 TABLE O ring Crosslinking O ring Mold Hardness
Compression time difference Thickness release difference set
Example Second Evaluation (mm) Evaluation properties Points
Evaluation % Evaluation Example 1 -19 .largecircle. 3.10
.largecircle. .largecircle. 1 .largecircle. 1 .largecircle. Example
2 -18 .largecircle. 3.10 .largecircle. .largecircle. 2
.largecircle. 2 .largecircle. Example 3 -12 .largecircle. 3.12
.largecircle. .largecircle. 2 .largecircle. 2 .largecircle. Example
4 -16 .largecircle. 3.12 .largecircle. .largecircle. 2
.largecircle. 2 .largecircle. Example 5 -17 .largecircle. 3.12
.largecircle. .largecircle. 2 .largecircle. 2 .largecircle.
Comparative 120 -- 3.20 X X (70) -- (19) -- Example 1 Comparative
13 X 3.10 .largecircle. .largecircle. 4 X 2 .largecircle. Example 2
Comparative -15 .largecircle. 3.15 X .largecircle. 3 X 1
.largecircle. Example 3 Comparative -25 .largecircle. 3.14 X
.largecircle. 3 X 4 X Example 4 Comparative -3 X 3.17 X
.largecircle. 3 X 2 .largecircle. Example 5 Comparative -11
.largecircle. 3.16 X X 1 .largecircle. 10 X Example 6 Comparative
-23 .largecircle. 3.16 X .largecircle. 2 .largecircle. 2
.largecircle. Example 7 Comparative 10 X 3.11 .largecircle. X 2
.largecircle. 11 X Example 8 Comparative 60 X 3.08 .largecircle. X
4 X 16 X Example 9 Comparative -2 X 3.10 .largecircle. X 4 X 2
.largecircle. Example 10 Comparative .+-.0 X 3.10 .largecircle. X 2
.largecircle. 2 .largecircle. Example 11 Comparative 30 X 3.12
.largecircle. X 4 X 7 X Example 12 Comparative 1 X 3.12
.largecircle. X .+-.0 .largecircle. 2 .largecircle. Example 13
Comparative 6 X 3.09 .largecircle. X 3 X 1 .largecircle. Example 14
Comparative -10 X 3.09 .largecircle. X 5 X 5 X Example 15
Comparative -14 .largecircle. 3.13 .largecircle. .largecircle. 5 X
10 X Example 16 Comparative 20 X 3.12 .largecircle. .largecircle. 7
X 6 X Example 17 Comparative 0 X 3.10 .largecircle. .largecircle. 6
X 2 .largecircle. Example 18 Comparative -7 X 3.15 X .largecircle.
1 .largecircle. 1 .largecircle. Example 19 Comparative -15
.largecircle. 3.11 .largecircle. .largecircle. 3 X 1 .largecircle.
Example 20 Comparative -17 .largecircle. 3.11 .largecircle.
.largecircle. 3 X 1 .largecircle. Example 21 Comparative -10 X 3.11
.largecircle. .largecircle. 2 .largecircle. 1 .largecircle. Example
22
* * * * *